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Abstract

Introduction

The sensation of palpitations may either be the initial or the only symptom of cardiac
arrhythmia. We describe a case of an apparent clear temporal relationship between
standard ibuprofen dosing and palpitations. A review of the medical literature revealed
this to be, to the best of our knowledge, the first reported case of this type.

Case presentation

A 13-year-old Caucasian girl initially presented to our clinic with hamstring tendinitis.
She was commenced on a medication regimen of paracetamol and ibuprofen. After the
third ibuprofen dose, she experienced palpitations. These were associated with lower
chest and/or upper abdominal discomfort, and a feeling of being hot and sweaty. Her
symptoms ceased upon the cessation of ibuprofen therapy.

Conclusion

Cardiac arrhythmia is a potentially fatal disorder that may exhibit heart palpitations
as its initial (or only) symptom. The prompt recognition of the cause of the symptom
can reduce mortality and morbidity associated with any underlying pathological processes.
There is a need to investigate cases of recurrent palpitations so as to exclude underlying
structural cardiac pathology and/or abnormal cardiac rhythm.

Introduction

Tendinitis, or the inflammation of a tendon, is a musculoskeletal disorder that is
commonly seen in patients in general practice clinics. It is usually treated with
a combination of rest, simple analgesics, a non-steroidal anti-inflammatory drug (NSAID)
and physical rehabilitation. In this case report, we describe a case of cardiac palpitations
that temporally appears to be caused by standard ibuprofen dosing, an event that has
not been previously described in the medical literature.

Case presentation

A 13-year-old Caucasian girl weighing 45 kg was examined in a general practice clinic
with a short history of left posterior thigh pain. There was no obvious precipitant
condition for her complaint. She reported no significant medical history, took no
medications and had no allergies. There was also no significant family medical history.
A clinical diagnosis of left hamstring tendinitis was made. She was commenced on a
regimen of paracetamol 1 g qid prn, ibuprofen 400 mg tds, and a gentle exercise and
stretching program.

Shortly after taking the third 400 mg dose of ibuprofen, she felt hot and sweaty,
and reported a sensation of palpitations. There was associated lower chest and upper
abdominal discomfort, but she felt no frank chest or abdominal pain. No other symptoms,
in particularly those suggestive of either an allergic reaction or an acute coronary
syndrome, were noted.

Our patient continued with ibuprofen treatment for another day, with exacerbation
of her symptoms after each ibuprofen dose. After informing her mother of her symptoms,
her ibuprofen medication was discontinued. Her symptoms ceased thereafter.

Upon clinical review a few days later, she was found well with a pulse of 70. An electrocardiogram
(ECG) test demonstrated sinus arrhythmia with no abnormality (Figure 1). Her echocardiography result was normal. Subsequent review by a pediatric cardiologist
elicited no abnormality. Further review in the clinic determined that her symptoms
had not recurred. After discussion with our patient and her mother, a decision was
made to not rechallenge her with ibuprofen.

Discussion

Ibuprofen was the first non-aspirin NSAID to be approved for over-the-counter (OTC)
use, and is widely considered to be the best tolerated drug of its class [1]. Previous studies [2,3] have demonstrated that adverse drug reactions (ADR) to NSAIDs predominantly involve
the skin, the gastrointestinal tract, and the respiratory system. Although it had
been previously suggested that ibuprofen may be involved in the development of ventricular
arrhythmia [4], only recently has ibuprofen been demonstrated to produce arrhythmia both in vitro and in vivo (in guinea pigs) [5]. This is achieved by a dose-dependent shortening of the cardiac action potential
(AP), and shortening of the effective refractory period (ERP). This had resulted in
a decrease of excitation propagation within the heart, which may provide substrate
for an arrhythmogenic reentry circuit.

Cardiac arrhythmia secondary to ibuprofen overdose has been described in the medical
literature. McCune and O'Brien reported the induction of atrial fibrillation (AF)
in a previously-well 35-year-old man [6]. Meanwhile, Menzies et al. reported a case of broad complex tachycardia secondary to fulminant hyperkalaemia
induced by ibuprofen overdose [7]. Interestingly, Gurfinkel et al. [8] have found that the intravenous administration of ibuprofen could immediately suppress
arrhythmia during a cardiac electrical storm, but this work was conducted in the presence
of decompensated cardiopathy, a condition not shared by the our patient. That our
patient experienced only symptoms common to those associated with the sensation of
palpitations, with no symptoms suggestive of an allergic aetiology, suggests that
this case was not one of Kounis syndrome [9], which has recently been reported after routine ibuprofen use [10].

Conclusion

Our patient has suffered no recurrence of her symptoms, and in the absence of ibuprofen
rechallenge, it is probable that standard dose ibuprofen was the causative link with
her symptoms of palpitations. No firm conclusion can be drawn as to the underlying
pathophysiological mechanism of her symptoms. This case appears to be the first case
report in the medical literature of an event adverse to cardiac arrhythmia following
standard oral ibuprofen administration.

Cardiac arrhythmia is a potentially fatal disorder that may exhibit heart palpitations
as its initial (or only) symptom. The recognition of drug-induced cardiac disturbance
is necessary to prevent the progression of symptoms to a more serious adverse event,
and to avoid reexposing patients to ibuprofen with resultant recurrent cardiac arrhythmia.
Further research is required to identify the pathophysiological mechanism of ibuprofen-induced
cardiac arrhythmia.

Competing interests

The author declares that they have no competing interests.

Consent

Written informed consent was obtained from the mother of our patient for publication
of this case report and any accompanying images. A copy of the written consent is
available for review by the Editor-in-Chief of this journal.

Acknowledgements

The author would like to thank Tonia Mezzini for her assistance with the preparation
of the manuscript.

References

Moore N: Ibuprofen: a journey from prescription to over-the-counter use.